Implemented function stubbing

include/recomp_port.h

@@ -70,6 +70,7 @@ namespace RecompPort {
         ELFIO::Elf_Half section_index;
         bool ignored;
         bool reimplemented;
+        bool stubbed;
     };
 
     enum class RelocType : uint8_t {
@@ -113,6 +114,8 @@ namespace RecompPort {
         std::vector<Section> sections;
         std::vector<Function> functions;
         std::unordered_map<uint32_t, std::vector<size_t>> functions_by_vram;
+        // A mapping of function name to index in the functions vector
+        std::unordered_map<std::string, size_t> functions_by_name;
         std::vector<uint8_t> rom;
         // A list of the list of each function (by index in `functions`) in a given section
         std::vector<std::vector<size_t>> section_functions;
@@ -124,7 +127,8 @@ namespace RecompPort {
             sections.resize(elf_file.sections.size());
             section_functions.resize(elf_file.sections.size());
             functions.reserve(1024);
-            functions_by_vram.reserve(1024);
+            functions_by_vram.reserve(functions.capacity());
+            functions_by_name.reserve(functions.capacity());
             rom.reserve(8 * 1024 * 1024);
             executable_section_count = 0;
         }

src/config.cpp

@@ -100,7 +100,7 @@ RecompPort::Config::Config(const char* path) {
 
 		// Patches section (optional)
 		const toml::value& patches_data = toml::find_or<toml::value>(config_data, "patches", toml::value{});
-		if (patches_data.type() == toml::value_t::empty) {
+		if (patches_data.type() != toml::value_t::empty) {
 			// Stubs array (optional)
 			get_stubbed_funcs(stubbed_funcs, patches_data);
 

src/main.cpp

@@ -665,6 +665,7 @@ bool read_symbols(RecompPort::Context& context, const ELFIO::elfio& elf_file, EL
                 if (num_instructions > 0) {
                     context.section_functions[section_index].push_back(context.functions.size());
                 }
+                context.functions_by_name[name] = context.functions.size();
                 context.functions.emplace_back(
                     vram,
                     rom_address,
@@ -1069,6 +1070,19 @@ int main(int argc, char** argv) {
 
     fmt::print("Working dir: {}\n", std::filesystem::current_path().string());
 
+    // Stub out any functions specified in the config file.
+    for (const std::string& stubbed_func : config.stubbed_funcs) {
+        // Check if the specified function exists.
+        auto func_find = context.functions_by_name.find(stubbed_func);
+        if (func_find == context.functions_by_name.end()) {
+            // Function doesn't exist, present an error to the user instead of silently failing to stub it out.
+            // This helps prevent typos in the config file or functions renamed between versions from causing issues.
+            exit_failure(fmt::format("Function {} is stubbed out in the config file but does not exist!", stubbed_func));
+        }
+        // Mark the function as stubbed.
+        context.functions[func_find->second].stubbed = true;
+    }
+
     //#pragma omp parallel for
     for (size_t i = 0; i < context.functions.size(); i++) {
         const auto& func = context.functions[i];

src/recompilation.cpp

@@ -997,6 +997,8 @@ bool RecompPort::recompile_function(const RecompPort::Context& context, const Re
         "    int c1cs = 0; \n", // cop1 conditional signal
         func.name);
 
+    // Skip analysis and recompilation of this function is stubbed.
+    if (!func.stubbed) {
         // Use a set to sort and deduplicate labels
         std::set<uint32_t> branch_labels;
         instructions.reserve(func.words.size());
@@ -1065,7 +1067,7 @@ bool RecompPort::recompile_function(const RecompPort::Context& context, const Re
 
             // Process the current instruction and check for errors
             if (process_instruction(context, func, stats, skipped_insns, instr_index, instructions, output_file, false, needs_link_branch, num_link_branches, reloc_index, needs_link_branch, is_branch_likely, static_funcs_out) == false) {
-            fmt::print(stderr, "Error in recompilation, clearing {}\n", output_path.string() );
+                fmt::print(stderr, "Error in recompilation, clearing {}\n", output_path.string());
                 output_file.clear();
                 return false;
             }
@@ -1083,6 +1085,7 @@ bool RecompPort::recompile_function(const RecompPort::Context& context, const Re
             // Advance the vram address by the size of one instruction
             vram += 4;
         }
+    }
 
     // Terminate the function
     fmt::print(output_file, ";}}\n");